1. Technical Field
The present disclosure relates to printed circuit boards (PCBs) and, particularly, to a PCB which can reduce fiber-weave effect.
2. Description of Related Art
Typical PCBs are constructed from various woven fiberglass fabrics, strengthened and bound together with epoxy resin. The fiberglass and epoxy resin may have different levels of permittivity respectively, presenting a non-homogeneous medium for signal transmission. The non-homogeneous medium in the PCBs may influence signal transmission, called fiber-weave effect. An ordinary method for reducing fiber-weave effect is a zig-zag routing mode in the PCBs.
Referring to FIG. 1, an ordinary PCB 10 is designed in a Zig-zag routing mode. The PCB 10 includes two differential signal pairs 13 and 17. The differential signal pair 13 includes a positive differential signal line 12 and a negative differential signal line 14. The differential signal pair 17 includes a positive differential signal line 16 and a negative differential signal line 18. The differential signal lines 12, 14, 16, and 18 are designed in zig-zag shape which can reduce fiber-weave effect. However, the PCB designed in zig-zag routing mode may increase layout space and complexity, and is time-consuming.